Manual override apparatus for electrohydraulic valve control station

ABSTRACT

Manual override apparatus for a proportional electrohydraulic control valve having mechanical override pushbuttons and an electric control unit therefor having a pivoted operating handle or lever, the apparatus including a bracket pivotally mounted on the body of the central valve and supporting the control unit for resiliently opposed movement about a pivot axis from a normal position. The control unit is fixed to the bracket, and a Ushaped plunger bar also fixed to the bracket has depending legs terminating outwardly adjacent the pushbuttons to actuate one of the pushbuttons when the control unit handle is tilted through such a range of movement as to cause tilting of the bracket.

[ Sept. 18, 1973 MANUAL OVERRIDE APPARATUS FOR ELECTROHYDRAULIC VALVE CONTROL STATllON inventor: Francis Duncan Mills, Henrico County, Va.

[73] Assignee: Baker Equipment Engineering Co.

1ne., Richmond, Va.

Filed: July 18, 1972 Appl. No.: 273,028

1/1943 Jeffrey et al. 251/130 8/1960 Fletcher et al 91/453 X Primary Examiner-Arnold Roseruthal Attorney-Thomas B. Van Poole et al.

[57] ABSTRACT Manual override apparatus for a proportional electrohydraulic control valve having mechanical override pushbuttons and an electric control unit therefor having a pivoted operating handle or lever, the apparatus including a bracket pivotally mounted on the body of the central valve and supporting the control unit for resiliently opposed movement about a pivot axis from a normal position. The control unit is fixed to the bracket, and a U-shaped plunger bar also fixed to the bracket has depending legs terminating outwardly adjacent the pushbu'ttons to actuate one of the pushbuttons when the control unit handle is tilted through such a range of movement as to cause tilting of the bracket.

12 Claims, 3 Drawing, Figures MANUAL OVERRIDE APPARATUS FOR ELECTROHYDRAULIC VALVE CONTROL STATION BACKGROUND AND OBJECTS OF THE INVENTION The present invention relates in general to control devices for controlling operation of boom structures, for example to regulate extension, elevation and rotation of an extendable boom such as may be employed on fire fighting and rescue equipment, aerial tower type vehicles used for servicing elevated electrical systems, working on trees, servicing or cleaning elevated surfaces or objects such as large aircraft, and the like. More particularly, the present invention relates to the incorporation of manual override means with a bank of electrohydraulic control valves and associated handle or lever operated electric control units for controlling a pivotally mounted extendable or articulated boom, whereby the operator may operate control handles or levers through a limited range to electrically activate control valves in a hydraulic system for regulating extension, elevation and rotation movement of the boom having a personnel basket or platform on the outer end thereof, and wherein movement of the control handles or levers beyond the limited range effects manual actuation of the hydraulic control valves to override the electrical control system, for example in the event of electrical failure.

Service and maintenance trucks have been available for a number of years which are of the type generally referred to as aerial tower vehicles wherein some type of boom structure is pivotally mounted for movement about a horizontal axis on a base or mounting structure which is journaled on the vehicle for rotation about a vertical axis, and a personnel supporting basket or platform structure is pivotally mounted on the upper end of the boom. Typically, control valves for a hydraulic control system controlled by manually operable levers or knobs at a console adjacent the pedestle of the boom structure and/or bya control handle or handles on the workers platform are provided for operation by personnel at the pedestle and on the elevated platform to permit them to remotely control the motors orhydraulic cylinder units which cause the raising and lowering and swinging movements of the boom structure and thereby enable them to move the platform to suitable elevated positions for working on high objects. Such service and maintenance trucks of the aerial tower type have been commonly used as fire fighting A been used,for example as the control console at the base of the boom, comprises a side-by-side stacked array of electric control devices, such as pivoted handle or pivoted, lever operated potentiometer and resistor networks, controlling electrically operated electrohydraulic servo valves arranged in a stacked array, wherein a set of three ofsuch servo valves and associated electric controls are provided for controlling hydraulic systems regulating extension, elevation and rotation of the boom. An example of such control valves and electric controls are the Model 60 Series proportional electrohydraulic control valve and the Model 60 Series electrical control therefor manufactured by Moog, Inc. of East Aurora, N.Y. While the Moog Model 60 Series proportional electrohydraulic control valve has manual override facilities incorporated therein, these are in the form of manual override pushbuttons projecting from opposite sides of what is termed the motor cap which rises from the main body of the electrohydraulic control valve and must be operated by moving the hand from the handle of the electric control unit to the appropriate side of the control valve motor cap for the particular direction of movement desired for the boom and manual pressing of the pushbutton inwardly. This requires the operator to instantly recall, under the stress of an emergency situation arising upon electrical failure of the system, the location of the proper pushbutton to depress and the need to manually operate the manual override pushbutton.

An object of the present invention is the provision of a novel attachment for a stacked array of electrohydraulic control valves and handle or lever operated electric control units therefor, wherein the operator needs only to move the pivoted handle or control lever for the electric control unit beyond the normal range ofmovement therefor in the desired direction to effect operation in the proper direction of manual override means incorporated in the electrohudraulic control valve.

Another object of the present invention is the provision of a-novel bracket and plunger bar assemblyfor use with pivoted handle operated electric control stations and proportional electrohydraulic control valves having manual override pushbuttons, for hydraulic regulation of plural axis movement of extendable booms and the like, wherein the handles of the electric control units are moved by the operator through a selected angular range for normal electrical activation of the electrohydraulic control valves, and wherein manual movement of the control handles of the electric control units beyond that selected range effects actuation of the ap-- propriate-manual override pushbutton of the electrohydraulic control valve .to provide manual override con- Y trol in the event of electrical failure.

[Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, ,taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a front elevation view of a manual override actuating attachment for a stacked] array of electrohydraulic control valves and electric control units providing extension, elevation, and rotation control for a boom, embodying the present invention;

FIG. 2 is aside elevation view thereof; and

FIG. 3 is a somewhat diagrammatic vertical section view through one of the electrohydraulic control valves with which the apparatus-of the present invention may be used.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures, there is illustrated in schematic section in FIG. 3 and in the lower portions of FIGS. 1 and 2, a side-by-side stacked array of three electrically operated servo valves commonly referred to commercially as proportional electrohydraulic control valves, which are indicated generally by the reference character 10, a specific example of which is the Moog Model 60 Series proportional electrohydraulic control valve manufactured and sold by Moog, Inc. of East Aurora, N.Y. The three electrohydraulic control valves making up the stacked array are indicated in FIG. 1 by the reference characters A, 10B and 10C. As indicated in the schematic section view of the electrohydraulic control valve 10 in FIG. 3, the control valve 10 comprises a lower main body portion 11 of elongated, generally rectangular configuration closed at opposite ends by cover plates 12a and 12b and having an upwardly extending rectangular housing portion 13, commonly referred to as the motor cap,-which is covered by a top cover plate 13a and which includes a lower compartment housing an electrically force motor or electromagnetic motor and an upper compartment housing an electrical terminal block 14. The force motor in the lower compartment is indicated generally by the reference character 15 and includes a permanent magnet and associated pole pieces 15a, a'movable armature 15b, a flexure tube 150, a flapper and feedback wire 15d connected thereto, a pair of nozzles 15e adjacent the flapper 15d, and a spool 15f movable in the main body portion for controlling flow of hydraulic fluid through the hydraulic circuit. The main body portion has upper and lower pairs of bolt openings extending therethrough transversely of the axis of the spool adjacent the opposite cover plates 12a, 12b, to receive the through bolts 1 la for assembling the control valve 10A, 10B and 10C in the side-by-side stacked array, for example with hydraulic manifold 16 mounted at one end of the stack in conventional fashion to simplify plumbing of the hydraulic pressure and return lines to the pressure and return conduits extending transversely to the spool axis through the valve bodies 11. Manual override pushbuttons 17 project from oppositefront and rear walls of the motor cap 13, which are normally designed for direct manual operation by thumb and forefinger control.

The electromagnetic motors 15 of the control valve 10A, 10B and 10C are respectively controlled by adjustable resistor type control unitsindicated generally at 18, three of which are shown at 18A, 18B and 18C, each of which comprises a generally rectangular housing 19 containing a network of resistors and a potenti ometer, and a pivoted operating handle or lever 20 having a normally vertically extending arm 20a and a horizontal shaft portion connected thereto coupled, for example by a sector gear and pinion, with the wiper arm of a potentiometer within the housing 19. Suitable stops, indicated in broken lines at 19b in FIG. 2, are provided within or externally of the housing 19 in the path of movement of a lug or pin indicated'at 20b, projecting from the horizontal shaft controlled by the arm 20a, to limit movement of the handle 20 through a range of about 30 in either direction from the vertical position.

The housing 19 of each of the control stations or electrical control units 18A, 18B and 18C are each fixed by bolts 19a to the vertical flange 21a of a right angle mounting bracket 21 having a horizontal flange or plate portion 21b. Downwardly extending right angle journal or bearing members 22 are welded to the horizontal flange portion 21b of the bracket 21, defining apertured ears to receive a threaded pivot pin 23 which also extends through upwardly projecting apertured ear portions of similar bearing members 24 welded to and rising from a mounting plate 25. The mounting plate 25 is secured by screws or similar fasteners to the top cover plate 13a at the top of the motor cap 13 of the associated control valve 10.

The plate 25 is elongated in the direction of the major dimension of the main body portion 11 of the associated control valve and has a pair of compression springs 26 surrounding locating posts 26a adjacent the opposite ends of plate 25. Springs 26 bear upwardly against the lower surface of the horizontal flange or plate portion 21b of the bracket 21 to normally maintain the bracket 21 and the control station 18 mounted thereon in the vertical position illustrated in FIG. 2. Also welded or otherwise fastened to the horizontal flange or plate 21a of each of the units is an elongated U-shaped plunger bar 28 having a horizontal mid portion 28a and downwardly extending, slightly convergent leg portions 28b and 280 whose lower ends are slightly rounded, as indicated at 28d. The lower ends 28d of the plunger bar legs 28b, 28c, bear against extension head members 29 for each of the override pushbuttons 17 to operate the pushbuttons. The extension head members 29 have a cylindrical exterior, rendering them freely slidable along the axes of the associated pushbuttons 17in concave cylindrical cavities 30 machined in the main body casting 11, and the head members are held in these cavities 30 by a retainer strap 31 secured at its downturned ends to upper through bolts 11a holding the bodies 11 in stacked array.

What is claimed is: v

l. A control valve assembly for control of movements of a boom structure, comprising an electrically operated control valve for controlling flow of hydraulic fluid to driving devices for the boom, the control valve including a main valve body and a pair of mechanical override pushbuttons projecting from the valve body movable inwardly along reciprocation axes from projected positions for mechanically actuating the control valve to establish selected hydraulic flow conditions, an electric control unit coupled to the control valve for supplying electrical signals thereto to activate the control valve to establish selected hydraulic flow conditions, the control unit having a housing and an operating handle movable about a pivot axis relative to the housing through a selected range in opposite directionsfrom a center position; a mounting assembly for pivotally mounting said control unit on said valve body including a support member mounted on said valve body for pivotal movement about a horizontal pivot axis, fastening means fixing the control unit housing on said support member, resilient means for continuously urging said control unit housing to a normal centered position, and a pair of actuating arms fixed to said support member and depending to positions outwardly adjacent said override pushbuttons to effect actuation of the adjacent override pushbutton when the operating handle is moved from said center position a distance greater than said selected range causing tilting movement of said support member about said horizontal pivot axis. i

2. A control valve assembly as defined in claim 1, wherein said support member for each respective control unit comprises a bracket having an upwardly projecting vertical flange to which the control unit housing is fixed and a horizontal flange having depending apertured ear members extending therefrom, and a pivot pin mounted on said valve body and extending through said ear members to define said horizontal pivot axis.

3. A control valve assembly as defined in claim 2, including an inverted generally U-shaped plunger bar for each of the respective brackets including an elongated horizontal intermediate portion fixed to the horizontal flange of the bracket and a pair of downwardly extending, slightly convergent legs at opposite ends of said intermediate portion defining said pair of actuating arms.

4. A control valve assembly as defined in claim 2, wherein said resilient means comprises a pair of coil springs arranged along vertical axes spaced oppositely from said horizontal pivot axis and having their upper ends bearing upwardly against said horizontal flange of the bracket for the associated control unit, and means defining a stationary bearing surface for the lower ends of said springs.

5. A control valve assembly as defined in claim 3, wherein said resilient means comprises a pair of coil springs arranged along vertical axes spaced oppositely from said horizontal pivot axis and having their upper ends bearing upwardly against said horizontal flange of the bracket for the associated control unit, and means defining a stationary bearing surface for the lower ends of said springs.

6. A control valve assembly as defined in claim ii, in-

cluding extension head members bearing against the' outer ends of each of said override pushbuttons and supported for axial movement along the axes of the pushbuttons, said actuating arms having lower end portions bearing against said head members to displace the latter and their associated pushbuttons inwardly upon selected tilting movement of the bracket.

'7. A control valve assembly as defined in claim 3, including extension head members bearing againstthe outer ends of each of said override pushbuttons and supported for axial movement along the axes of the pushbuttons, said actuating arms having lower end portions bearing against said head members to displace the latter and their associated pushbuttons inwardly upon.

selected tilting movement of the bracket.

8. A control valve assembly for control of movements of a boom structure, comprising a stacked array of electrically operated control valves for controlling flow of hydraulic fluid to hydraulic power driving devices for extension, elevation and rotation of the boom, the control valves each including a main valve body having a pedestle portion rising therefrom and a pair of mechanical override pushbuttons projecting from opposite sides of said pedestle portion movable inwardly along a common reciprocation axis from projected positions for mechanically actuating the associated control valve to establish selected hydraulic flow conditions, an electric control unit for each respective control valve for supplying electrical signals thereto to activate the associated control valve to establish selected hydraulic flow conditons, each control unit having a housing and an operating handle movable about a pivot axis relative to the housing through a selected range in opposite directions from a center position; a mounting assembly for pivotally mounting each said control unit on the valve body of the associated control valve including a support member mounted on said pedestle portion for pivotal movement about a horizontal pivot axis, fastening means fixing the control unit housing on said support member, resilient means for continuously urging said control unit housing to a normal centered position, and a pair of actuating arms fixed to said support member and depending downwardly alongside saidpedestle portion to positions outwardly adjacent said overrride pushbuttons to effect actuation of the adjacent override pushbutton when the operating handle is moved from said center position a predetermined distance greater than said selected range causing tilting movement of said support member about said horizontal pivot axis and consequent tilting movement of said actuating arms to move one of said override pushbuttons inwardly from its projected position.

9. A control valve assembly as defined in claim 8,

wherein said support member for each respective control unit comprises a bracket having an upwardly projecting vertical flange to which the control unit housing is fixed and a horizontal flange having depending apertured ear members extending therefrom, and a pivot pin mounted on the top of said pedestle portion of said valve body and extending through said ear members to define said horizontal pivot axis.

Mi. A control valve assembly as defined in claim 9,

including an inverted generally U-shaped plunger bar for each of the respective brackets including an elongated horizontal intermediate portion fixed to the horizontal flange of the bracket and a pair of downwardly extending, slightly convergent legs at opposite ends of said intermediate portion defining said pair of actuating arms.

111. A control valve assembly as defined in claim 10', wherein said resilient means comprises a pair of coil springs arranged along vertical axes spaced oppositely from said horizontal pivot axis and having their upper ends bearing upwardly against said horizontal flange of the bracket for the associated control unit, and means defining a stationary bearing surface for the lower ends of said springs.

12. A control valve assembly as defined in claim 10, including extension head members bearing against the outer ends of each of said override pushbuttons and supported for axial movement along the axes of the pushbuttons, said actuating arms having lower end portions bearing against said head members to displace the latter and their associated pushbuttons inwardly upon selected tilting movement of the bracket.

t t t W *l' 

1. A control valve assembly for control of movements of a boom structure, comprising an electrically operated control valve for controlling flow of hydraulic fluid to driving devices for the boom, the control valve including a main valve body and a pair of mechanical override pushbuttons projecting from the valve body movable inwardly along reciprocation axes from projected positions for mechanically actuating the control valve to establish selected hydraulic flow conditions, an electric control unit coupled to the control valve for supplying electrical signals thereto to activate the control valve to establish selected hydraulic flow conditions, the control unit having a housing and an operating handle movable about a pivot axis relative to the housing through a selected range in opposite directions from a center position; a mounting assembly for pivotally mounting said control unit on said valve body including a support member mounted on said valve body for pivotal movement about a horizontal pivot axis, fastening means fixing the control unit housing on said support member, resilient means for continuously urging said control unit housing to a normal centered position, and a pair of actuating arms fixed to said support member and depending to positions outwardly adjacent said override pushbuttons to effect actuation of the adjacent override pushbutton when the operating handle is moved from said center position a distance greater than said selected range causing tilting movement of said support member about said horizontal pivot axis.
 2. A control valve assembly as defined in claim 1, wherein said support member for each respective control unit comprises a bracket having an upwardly projecting vertical flange to which the control unit housing is fixed and a horizontal flange having depending apertured ear members extending therefrom, and a pivot pin mounted on said valve body and extending through said ear members to define said horizontal pivot axis.
 3. A control valve assembly as defined in claim 2, including an inverted generally U-shaped plunger bar for each of the respective brackets including an elongated horizontal intermediate portion fixed to the horizontal flange of the bracket and a pair of downwardly extending, slightly convergent legs at opposite ends of said intermediate portion defining said pair of actuating arms.
 4. A control valve assembly as defined in claim 2, wherein said resilient means comprises a pair of coil springs arranged along vertical axes spaced oppositely from said horizontal pivot axis and having their upper ends bearing upwardly against said horizontal flange of the bracket for the associated control unIt, and means defining a stationary bearing surface for the lower ends of said springs.
 5. A control valve assembly as defined in claim 3, wherein said resilient means comprises a pair of coil springs arranged along vertical axes spaced oppositely from said horizontal pivot axis and having their upper ends bearing upwardly against said horizontal flange of the bracket for the associated control unit, and means defining a stationary bearing surface for the lower ends of said springs.
 6. A control valve assembly as defined in claim 1, including extension head members bearing against the outer ends of each of said override pushbuttons and supported for axial movement along the axes of the pushbuttons, said actuating arms having lower end portions bearing against said head members to displace the latter and their associated pushbuttons inwardly upon selected tilting movement of the bracket.
 7. A control valve assembly as defined in claim 3, including extension head members bearing against the outer ends of each of said override pushbuttons and supported for axial movement along the axes of the pushbuttons, said actuating arms having lower end portions bearing against said head members to displace the latter and their associated pushbuttons inwardly upon selected tilting movement of the bracket.
 8. A control valve assembly for control of movements of a boom structure, comprising a stacked array of electrically operated control valves for controlling flow of hydraulic fluid to hydraulic power driving devices for extension, elevation and rotation of the boom, the control valves each including a main valve body having a pedestle portion rising therefrom and a pair of mechanical override pushbuttons projecting from opposite sides of said pedestle portion movable inwardly along a common reciprocation axis from projected positions for mechanically actuating the associated control valve to establish selected hydraulic flow conditions, an electric control unit for each respective control valve for supplying electrical signals thereto to activate the associated control valve to establish selected hydraulic flow conditons, each control unit having a housing and an operating handle movable about a pivot axis relative to the housing through a selected range in opposite directions from a center position; a mounting assembly for pivotally mounting each said control unit on the valve body of the associated control valve including a support member mounted on said pedestle portion for pivotal movement about a horizontal pivot axis, fastening means fixing the control unit housing on said support member, resilient means for continuously urging said control unit housing to a normal centered position, and a pair of actuating arms fixed to said support member and depending downwardly alongside said pedestle portion to positions outwardly adjacent said overrride pushbuttons to effect actuation of the adjacent override pushbutton when the operating handle is moved from said center position a predetermined distance greater than said selected range causing tilting movement of said support member about said horizontal pivot axis and consequent tilting movement of said actuating arms to move one of said override pushbuttons inwardly from its projected position.
 9. A control valve assembly as defined in claim 8, wherein said support member for each respective control unit comprises a bracket having an upwardly projecting vertical flange to which the control unit housing is fixed and a horizontal flange having depending apertured ear members extending therefrom, and a pivot pin mounted on the top of said pedestle portion of said valve body and extending through said ear members to define said horizontal pivot axis.
 10. A control valve assembly as defined in claim 9, including an inverted generally U-shaped plunger bar for each of the respective brackets including an elongated horizontal intermediate portion fixed to the horizontal flange of the bracket and a pair of downwardly extending, sLightly convergent legs at opposite ends of said intermediate portion defining said pair of actuating arms.
 11. A control valve assembly as defined in claim 10, wherein said resilient means comprises a pair of coil springs arranged along vertical axes spaced oppositely from said horizontal pivot axis and having their upper ends bearing upwardly against said horizontal flange of the bracket for the associated control unit, and means defining a stationary bearing surface for the lower ends of said springs.
 12. A control valve assembly as defined in claim 10, including extension head members bearing against the outer ends of each of said override pushbuttons and supported for axial movement along the axes of the pushbuttons, said actuating arms having lower end portions bearing against said head members to displace the latter and their associated pushbuttons inwardly upon selected tilting movement of the bracket. 